Sensors to sniff out environmental exposures

Tuning fork-based technologies to measure environmental health risks

Every day, as we go about our normal routines in the places we live and work, we are often unknowingly bombarded by small, air-borne particles found in the air. This increased exposure has been linked to diseases like asthma, where the number of cases has been increasing at an alarming rate for the last few decades, particularly in developed countries.

People are exposed to tens of thousands of different chemicals in our environment and these concentrations typically vary significantly throughout the day—presenting an enormous technical challenge to scientists. The prevailing evidence strongly suggests an increasing correlation between chemical exposure and disease. However, not everyone living in the same neighborhood has the same disease. People can be engaged in different activities, or have completely different genetic make-ups that may increase or decrease their susceptibility.

A better understanding of the environmental risks of chemical exposures as well as people’s susceptibility to that risk can be the key to better health. This will ultimately afford us the comfort of modern day living without the adverse consequences or undesirable side-effects, and help us focus our efforts to minimize pollutants that we are sensitive to while allowing more flexibility with those of less impact.

There is a great societal need for new technologies that can gather real-time individual exposure levels to toxicants relative to their micro- and immediate environment. This would provide us a better understanding of how exposure and individual genetic make-ups or activity levels are relevant to a population’s health.

By integrating state-of-the-art sensor, electronics and wireless communication technologies, our Center for Bioelectronics and Biosensors, with the generous support of federal agencies including the NIH/NIEHS, is leading a project to develop a novel wearable wireless sensor.  This sensor system mimics natural olfactory systems, and can be used in “real-world” applications. The system elements range from the nanometer to centimeter scale and are integrated to work cooperatively and perform detection of chemical analytes in complex “real-environments.”

Two versions of a prototype device have been developed thus far. The latest version is only slightly larger than the size of a deck of cards. A cell phone is being used to receive data from the sensor module as well as to store and to display the data.

We have already put the sensor module to tests in  “real-world” environments and applications such as detecting volatile organic compounds at Phoenix Sky Harbor International Airport, a gas station, at a location on the ASU Main campus, etc. The latest version of the device will include GPS capability, higher sensitivity, multiple analyte detection, more user-friendly controls, and switching to an smart phone-based user interface.